Evaluation of a spreadsheet-based COVID-19 contact-tracing tool (CTT) and determination of risk factors for SARS-CoV-2 transmission among hospital staff members.Setting: Tertiary hospital in Germany.Observational descriptive study on the application and acceptance of the CTT. Retrospective case-control study for SARS-CoV-2 transmission risk factor determination and for evaluation of the CTT's risk stratification algorithm. 3514 contacts of hospital staff members to 322 SARS-CoV-2-positive cases.A case-control study was performed to identify risk factors for SARS-CoV-2 transmission and for unprotected contacts among staff members. To evaluate strengths and weaknesses of the CTT performance statistics were analyzed and users completed a questionnaire measuring satisfaction and acceptance of the tool.P<0.005) more unprotected contacts to other staff members (25.5% vs. 9.6%) and more SARS-CoV-2 transmissions per contact (4.9% vs. 0.6%) than staff members with frequent contacts to patients. The profession “nurse or medical technical service” was associated with significantly (P<0.005) more unprotected contacts between staff members (11.0% vs. 2.6%) compared to the profession “physician”.In 2021, the CTT was used for the algorithm-based semi-automated management of 3514 in-hospital contacts. The tool determined the risk category of individual contacts and generated messages for the information of the local public health department, the in-hospital SARS-CoV-2 test center and all staff members who had contact to the index case. Staff members without regular contacts to patients had significantly (Digital tools can increase the efficiency of in-hospital contact tracing. The CTT enable a timely systematic analysis of risk factors among staff members. In late 2019, the outbreak of a novel viral pneumonia, which later became known globally as COVID-19, occurred in the city of Wuhan, China. Common symptoms of the disease include fever, cough, chest discomfort, olfactory and gustatory disturbances and in severe cases, dyspnea and bilateral lung infiltration.  SARS-CoVContact tracing is one of the most effective containment measures for SARS-CoV-2.  The aim With growing numbers of SARS-CoV-2-positive staff members, in November 2020 our paper-based procedure for in-hospital contact tracing reached its limits due to the high time requirements per case. For this reason, a spreadsheet-based contact tracing tool (CTT) was developed to automate essential steps of the hospital's contact tracing process. Here we report on the lessons learned from one year of semi-automated contact tracing in our hospital.The University Hospital Magdeburg is a tertiary hospital located in Central Germany. It has (state August 2022) 4706 staff members and treats about 50,000 patients annually. During the whole pandemic, the Section Infection Control (SIC) performed COVID-19 contact tracing among hospital's staff and inpatients. The SIC consists of two infection control physicians and seven infection control nurses.The CTT was developed in cooperation between the SIC and the hospital's IT department using Microsoft Excel 2016 and Visual Basic for Applications. Contacts were traced from 48 hours before symptom onset. The core of the CTT was a spreadsheet containing the contact list a. For eaMailing automation was realized by a macro using the Visual Basic's Outlook Application object and the Workbook. ExportAsFixedFormat function (for PDF creation). In the manner just described, lists with either category 1 contacts only, category 1, 2 and 2 vac contacts or all contacts were send to the public health department, to the in-hospital SARS-CoV-2 testing center, and to the SIC, respectively. The CTT also sent individual emails to all staff members on the contact list that informed about the requirement and the dates of PCR-testing and about the necessary contact precautions according to the contact's calculated risk classification.The spreadsheet was mailed to the SARS-CoV-2 positive employee and/or the supervisor. The spreadsheet data then were filled either by the quarantined employee according to his/her memories of contacts or on the supervisor's workplace computer after directly calling the index case and/or interviewing the coworkers about their contacts to the index case. Inquiries to the infection control team regarding the operation of the tool occurred but were uncommon (less than 25% of cases) and could usually be resolved within a few minutes. The data supplied by health care workers on the list were not double-checked by the SIC.In order to evaluate strengths and weaknesses of the CTT, the infection control nurses of the hospital (n = 7), who worked with the CTT, completed a questionnaire, which was composed of 16 items measuring the acceptance of various sub-aspects of this form of semi-automated contact tracing . The iteP < 0.005 in order to correct for multiple comparisons. Chi square test was also used to examine whether the risk classes determined by the algorithm allow significant predictions about the expected infection risks.All contact lists sent to SIC were analyzed retrospectively. The number of category 1, 2, 2 vac and 3 contacts were counted, as well as the number of PCR-appointments and emails send to the staff members, the public health department and the testing center. In order to determine the SARS-CoV-2 transmission rates, contacts were compared with the list of positive staff members. Transmission was assumed if infection occurred within 14 days of contact and no alternative source of infection (e.g. positive family member) was considered more likely. The data on gender, workplace and profession were added for the index cases. Data analysis were performed using Microsoft Excel 2016. The chi square test was used for the assessment of significant associations between risk factors and outcome variable with a significance level of st to December 31th 2021, SARS-CoV-2 was detected by PCR in 334 staff members, which corresponds to a seven-day incidence of 136 cases per 100.000. Further, the virus was detected by PCR in 182 in- or outpatients that were not treated primarily because of COVID-19 . Contact tracing was performed for 322 SARS-CoV-2-positive index cases (patients or staff members) using the CTT . Of the 3514 contacts, 151 (4.3%) were classified as category 1 contacts (mainly face to face contact or stay in the same room as the index for more than 30 minutes), 161 (4.6%) as category 2 contacts (no face to face contact but stay in same room as the index for less than 30 minutes), 353 (10.1%) as category 2 vac contacts  and 2849 (81.8%) as category 3 contacts (use of a FFP2 mask during the whole contact).All staff members with category 1 contacts were reported automatically to the public health department by the CTT. The public health department ordered a quarantine of 14 days for 80 of these 151 staff members. For 33 staff members the quarantine was shortened to 6 days and no quarantine was ordered for 38 staff members in order to maintain acute medical care. In addition, the CTT automatically arranged 1719 appointments for PCR testing at the hospital's testing centre for the 655 staff members with contacts of category 1, 2 or 2 vac. Regardless of the risk classification, all 3514 contacts were reported to SIC by the CTT. Finally, the CTT automatically generated and sent 3514 emails, one for each contact, that informed about the necessary infection control measures. Staff members with private SARS-CoV-2 contacts  were not followed up using CTT. Among 289 private contacts, there were 55 transmissions, corresponding to a transmission rate of 19%.Forty-nine staff members that were traced by the CTT became SARS-CoV-2-positive, which corresponds to a rate of 0.15 secondary infections per index case. The risk of SARS-CoV-2 transmission was dependent on the risk class of the contact (category 1: 11.3% (17/151); category 2: 3.1% (5/161); category 2 vac: 3.7% (13/353); category 3: 0.5% (14/2835). Thus it can be stated that the SARS-CoV-2 transmission risk differs considerably in the individual risk classes determined by the algorithm (P < 0.005) more unprotected contacts among each other compared to staff members with regular close patient contacts  more SARS-CoV-2 transmissions per contact in staff members without regular patient contacts compared to staff members with regular patient contacts . Within the group of staff members with regular patient contacts, the physicians had significant (P<0.005) less unprotected contacts compared to the nursing staff/medical technical assistants (contacts classified category 1 or 2: 2.6% vs. 11%). The risk of SARS-CoV-2 transmission, however, was not significantly different among both groups. Gender (P=0.01) was no independent risk factor for a higher rate of unprotected contacts or SARS-CoV-2 transmission.The analysis of contacts further showed that staff members without direct patient contacts had significantly (P<0.005) more likely infected after contact to SARS-CoV-2-positive staff members than after contact to SARS-CoV-2-positive patients. Among the 49 SARS-CoV-2 transmissions to staff members, other staff members were the source of infection in 41 cases (secondary attack rate (SAR) 2.0%) and patients in eight cases (SAR 0.6%). In 2021, 131 SARS-CoV-2-positive in- or outpatients had 1416 contacts to hospital staff members before they were diagnosed SARS-CoV-2-positive, either as an incidental finding at the routine PCR-test at admission or during the in-hospital stay. As FFP2 filtering facepiece respirators were compulsory for staff members to use for all patient contacts throughout 2021, 99% of contacts were category 3 contacts and less than 1% were category 2 or 2vacc contacts.Finally, staff members were significantly  received a questionnaire. The results are shown in At the very beginning of the SARS-CoV-2 pandemic, health-care workers faced an elevated risk of unprotected exposure to the virus.  In contret al. gave a pooled SAR of 21.1% [95% CI 17.4–24.8] for household contacts and a pooled SAR for hospitals of 3.4% [95% CI 1.0–6.9]. [From 334 SARS-CoV-2-positive staff members, 49 have been likely infected in the working environment, while 272 infections were considered as not hospital-acquired. In 13 cases, a link to a SARS-CoV-2 outbreak seems possible even if no plausible transmission route could be identified. The SAR of our staff members in cases of contacts to SARS-CoV-2-positive family members was 19%, while the rate for hospital contacts was 1.5% across all risk classes. In a meta-analysis, Thomson % 95% CI .4–24.8 fet al. and Schneider et al. [Staff members were significantly more likely to be infected by other SARS-CoV-2-positive staff members than by SARS-CoV-2-positive patients, as described by Emecenet r et al. ,19.Despite strict in hospital contact restrictions, SARS-CoV-2-positive index cases had an average of 10.9 contacts. Despite identical contact precaution rules, staff members without regular patient contacts  had significantly more unprotected contacts among each other than staff members with regular close patient contacts , which paradoxically resulted in a significant higher risk of virus transmissions among staff members with overall less person to person contacts. This reinforces previous findings ,21 that Within the group of staff members working close to the patient, in 2021 physicians had significantly fewer unprotected contacts compared to nursing/medical technical staff. We have no data on the total number of contacts of nurses or physicians to patients or co-workers, respectively, which limits the interpretation of the data and thus we cannot draw conclusions in regard to the infection control compliance among both professional groups. In contrast to nursing/medical technical staff, physicians often have an own office room, so that it is easier to spend meal and rest breaks alone than if there is only one shared recreation room on the ward for the whole team.et al.: 11% [et al. 11.7% for confirmed cases only  [et al. 11.3% [In our study 11.3 % of staff members with category 1 contacts became SARS-COV-2-positive within 14 days. This value essentially corresponds to the transmission values reported in the literature for unprotected contacts in hospitals  ; Zirbes l. 11.3% ). Converet al. [et al. [et al. [In response to the COVID-19 pandemic, different digital tools have been developed to assist contact tracing . The sofet al.  performe [et al.  describe [et al.  first us [et al. , 27.In summary, digital tools can increase the efficiency of in-hospital contact tracing. Despite some users reporting minor technical issues, the CTT proved to be an acceptable local solution for contact tracing in our hospital. By avoiding time consuming personal interviews, it reduced the time requirements for contact tracing, while simultaneously improving the data quality by avoiding an individual classification of risk-groups and enabling timely analysis of the compiled data. In principle, after adapting the parameters of the algorithm to the corresponding properties of a pathogen  this type of contact tracing can be used to trace other pathogens. In our opinion, the benefit of the tool is highest for infections with relatively long incubation periods, high reproductive numbers, and pre-symptomatic pathogen shedding or oligo- or asymptomatic courses. Also, others described local solutions that were born out of necessity at the beginning of the pandemic and were adapted later (1) (2). In-hospital epidemiological data are often available in situations, when general testing outside the hospital is not yet available e.g. because of limited diagnostic resources. By displaying the data in real time, e.g. in the form of a dashboard, in-hospital infection control teams as well as regional infection control authorities could quickly react on new trends in the spread of the pathogen.Lukas Bechmann MD: Conceptualization; Writing - Original Draft; Methodology; Data Curation; Investigation; Software; Visualization.Gernot Geginat MD: Conceptualization; Writing - Review & Editing; Visualization; Methodology; Validation; Supervision.


To investigate the effect of transcutaneous electrical acupoint stimulation (TEAS) on early cognitive function in elderly patients after single port thoracoscopic lobectomy.One hundred and nine patients who underwent single whole thoracoscopic lobectomy in Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January 2020 to October 2021 were included in this single-center, retrospective observational study. According to the treatment records, before anesthesia, 56 patients received TEAS (TEAS-group), and 53 patients applied electrodes at the same acupoint without electrical stimulation (control-group). Preoperative and postoperative cognitive function , serum neuron specific enolase (NSE), S100β protein and p-tau protein levels and postoperative complications were compared between the two groups.After operation, the MMSE of the TEAS-group was significantly better than that of the Control-group, with the MMSE of the TEAS-group returned to the preoperative level 72 hours after operation. Serum NSE, S100β and p-tau concentrations 24 hours and 72 hours after operation in the TEAS-group returned to their preoperative level and were significantly lower than those in the control-group. Hospitalization time of the TEAS-group was significantly shorter and hospitalization expenses were significantly lower comparing to the control-group.TEAS treatment could promote improved early postoperative cognitive function of elderly patients undergoing single port thoracoscopic lobectomy and could accelerate the recovery. With the increasing life expectancy and the increased incidence of lung cancer, more elderly patients are requiring treatment for non-small cell lung cancer (NSCLC). While surgery is still the primary treatment of lung cancer,4To date, there is no evidence showing the effectiveness of drug prevention strategies in reducing the occurrence of early postoperative cognitive dysfunction in elderly patients. Transcutaneous electrical acupoint stimulation (TEAS) is mainly a combination of electrical stimulation therapy and the traditional meridian theory of traditional Chinese medicine, which uses acupoint conduction to stimulate and subsequently improve the functional status of patients.7TEAS therapy can relieve clinical symptoms, improve hand dysfunction, and seems to further improve overall treatment of stroke patients.At present, the combination of TEAS with anesthesia is widely used in clinical practice as studies have found that TEAS could reduce postoperative analgesic requirement in patients undergoing surgery and expedite patients’ recovery.In this single-center, retrospective observational study, the records of 109 patients  who underwent single whole thoracoscopic lobectomy in Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January 2021 to October 2021 were reviewed. Before anesthesia, 56 patients received TEAS and were set as TEAS-group, and 53 patients applied electrodes at the same acupoint without electrical stimulation and were set as control-group. The study was approved by the hospital ethics committee (No. 20220103) and informed consent was taken from all patients.Age>60 yearsSingle port thoracoscopic lobectomy was performed2 < BMI ≤ 30 kg/m2Body mass index (BMI): 20 kg/mComplete medical recordsHistory of surgery within the past yearSerious complications resulting from surgery, central nervous system diseases or severe mental health diseases before the operationHistory of drug allergy before operationLong term oral administration of psychotropic or opioid drugs before operationAllergic patients with intolerance to TEASTEAS was initiated 30min before anesthesia. Acupoint selection Taiyang xue and Fengchi xue .Patients were monitored for noninvasive arterial blood pressure, peripheral capillary oxygen saturation (SpO2) and echocardiograms upon arrival at the operating room. Intravenous anesthesia induction was performed with propofol 1.5~2.5mg/kg, sufentanil 0.4μg/kg, and cisatracurium 0.2mg/kg. After successful induction of anesthesia, tracheal intubation was performed, and mechanical ventilation was started by connecting to the anesthesia machine. During the process, the oxygen flow rate, tidal volume and respiratory rate were 2 L/ minutes, 8–10 ml/kg and 10–14 times/ minutes, respectively. Anesthesia was maintained by target-controlled infusion (TCI) of remifentanil 1~4 ng/ml, propofol 1~4 μg/ml and continuous infusion of cisatracurium 0.06 mg/(kg·h) to keep the bispectral index (BIS) at 40~60 and the anesthesia nociception index(ANI) at 50~70. Sufentanil 0.1 μg/kg was given at the 30mins before the end of the operation for analgesia transition and 0.375% ropivacaine 20ml was given for intercostal nerve block upon skin closure. After that, the patient was returned to the postanesthesia care unit and was extubated when the indication for extubation was met.Patient-controlled intravenous analgesia (PCIA) was performed with sufentanil for all patients for two days. The analgesic drug formulation was Sufentanil 200μg + flurbiprofen 300mg, with normal saline to make up to 200 ml . The numeric rating scale (NRS) score were recorded and NRS score at rest and deep breathing was maintained at less than four.In the control-group, the electrodes were placed 2-cm beside Taiyang and Fengchi xue, 30min before anesthesia, without electrical stimulation. The anesthesia process was the same as that of the TEAS-group.The patients laid on their side, with their chest properly raised and slightly tilted forward. The affected upper limb was abducted and fixed. After confirming that the contralateral lung ventilation was good, routine disinfection and towel application were carried out. The surgical incision was between the anterior axillary line and the middle axillary line. The surgical incision of the upper lobe and the middle lobe was in the fourth intercostal space of the affected side. The incision of the lower lobe was in the fifth intercostal space. The length of the incision was about 3cm. After cutting the skin layer by layer, the intercostal muscle was opened, followed by opening of the pleura and entering the chest cavity. A soft incision protective sleeve was placed at the incision. Under the assistance of laparoscopy, the pulmonary ligament was released, the pulmonary artery, pulmonary vein and bronchus were separated in turn, lobectomy and lymphadenectomy were performed, and the thoracic closed drainage tube was placed at the incision.NES, S100β and p-tau were measured 24 hours before the operation and again 24 hours and 72 hours following the operation. Test method: venous blood was collected (3ml) and centrifuged at 3000r/minutes with a 3cm centrifugation radius at 4°C for five minutes. The supernatant was stored at -20°C. Prior to measurement, the blood sample was thawed for 30min. The concentrations of NES, S100β and p-tau in plasma were determined by enzyme-linked immunosorbent assay using Shanghai Kehua ST-360 microplate reader. The relevant kits were purchased from Wuhan bode Bioengineering Co., Ltd.Cognitive function was assessed by mini mental state examination (MMSE), 24 hours before the operation and 24- and 72 hours after the operation. The MMSE examination was conducted by trained nurses who are blinded to the information about grouping and acupoints. The MMSE included five orientation items: memory, attention and calculation, recall ability and language ability, with 30 excitement points. The higher the score, the better the cognitive function.operation time, intraoperative blood loss, hospitalization time, treatment cost, consumption of remifentanil, propofol and cisatracurium, extubation time, NRS score, PCIA press numbers and postoperative complications  were recorded.2 test. P<0.05 was considered statistically significant.Statistical analysis was done using SPSS 25.0 software. The measurement data were expressed by mean±standard deviation. The difference between groups was assessed using a t-test and variance analysis, respectively, and the count data was tested by χP>0.05). The hospitalization time of the TEAS-group was significantly shorter than that of the Control-group, resulting in a significantly lower overall hospitalization cost (P<0.05). However, there was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05).There was no significant difference between groups in the age or ratio of male to female patients, pathological type of lung cancer or coexisting diseases , P>0.05.o groups , P>0.05.P>0.05). Post-operatively (24 hours) there was a decrease in MMSE scores in both groups, with a greater decrease observed in the Control-group (P<0.001). Post-operatively (72 hours), the patients in the TEAS-group recovered their MMSE scores to pre-operative level (P<0.001).Pre-operatively, there was no difference in MMSE scores between the two groups , P>0.05.ol-group , P<0.001ve level , P<0.001P>0.05). The serum levels of NSE, S100β and p-Tau were increased 24 hours and 72 hours after operation in both groups, with significantly higher concentrations of all markers in the control-group (P<0.05). Post-operatively (72 hours), the patients in the TEAS-group recovered their serum levels of NSE, S100β and p-Tau to pre-operative concentrations (P<0.05).Pre-operatively, there was no significant difference in serum NSE, S100β and p-Tau concentrations between the two groups , P>0.05.ol-group , P<0.05.trations , P<0.05.P>0.05).There was one case of pulmonary infection, two cases of post-operative hemorrhage, three cases of post-operative hypoxemia and three cases of atelectasis in the Control-group . In TEASThe results of this study showed that the hospitalization time, treatment cost and serum NSE, S100β and p-Tau levels of the TEAS treatment group were significantly lower than those of the control-group, while the MMSE score was significantly higher than that of the control-group. TEAS treatment did not significantly increase post-operative complications, indicating that this method is suitable for elderly patients with single port thoracoscopic lobectomy, and can effectively promote the recovery of cognitive function in these patients.P<0.01); lower BIS at 10, 20, and 30 minutes before induction (P<0.01); lower levels of postoperative sufentanil consumption; lower number of PCIA attempts and effective rates (P<0.01); lower incidences of nausea at zero, six, 24, and 48 hours; and lower incidence of vomiting at 24 hours after surgery (P<0.05). The postoperative Observer’s Assessment of Alertness/Sedation (OAAS) scores were similar between the groups.In the study by Chen J et al.It shows that TEAS is a feasible method of sedation and postoperative analgesia. Similarly, Xiong W et al.At present, MMSE is adapted from the Mini Mental State Examination. This test can comprehensively, quickly and accurately reflect patients’ mental state and determine the degree of cognitive impairment. Because of its high sensitivity and specificity, MMSE is suitable for the evaluation of post-operative cognitive status in elderly patients.There was no significant difference in MMSE scores between the two groups. However, MMSE scores of patients in both groups were significantly decreased 24 hours post-operation, with a greater decrease observed in the control-group. Patients in the TEAS-group showed a recovery of MMSE scores to pre-operative levels 72h post-operation. This suggests that TEAS can significantly improve the early cognitive function of elderly patients after a single port thoracoscopic lobectomy.NSE is a cytoplasmic protein with enolase activity, which is synthesized and secreted by cerebral neurons.Certain pathological conditions result in abnormal phosphorylation of tubulin associated unit (Tau) protein that plays a role in maintaining the stability of microtubules in axons.22Other studies have shown that the improvement of cognitive function in patients with epilepsy may be related to the decrease of p-Tau protein level.It is a single center with a small sample size, and TEAS was only performed before surgery. However, Sun K et al.TEAS, combined with general anesthesia, can promote early post-operative cognitive function of elderly patients with single port thoracoscopic lobectomy, and can accelerate the post-operative recovery.XC conceived and designed the study. HC and JG collected the data and performed the analysis. XC was involved in the writing of the manuscript and is responsible for the integrity of the study. All authors have read and approved the final manuscript.


Gefitinib (GE) is a first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for patients with advanced non-small cell lung cancer (NSCLC) carrying EGFR activating mutations. However, drug resistance limits the clinical efficacy of gefitinib and ultimately leads to extremely poor clinical benefit. Meclofenamic acid (MA) is a non-steroidal anti-inflammatory drug (NSAID) that relieves moderate and severe pain. In the present study, we aim to determine the MA sensibilization of GE in NSCLC.MTT assay was conducted to determine the synergistic effect of MA with GE in GE-sensitive and -resistant cell lines based on the Chou–Talalay method. The Annexin V-PI flow cytometry analysis was conducted to evaluate apoptosis. Western blot assay was used to detect alterations of EGFR downstream molecules. Tritium-labeled GE accumulation analysis was used to determine the efflux activity of GE. Dot blot assays were conducted to determine m6A levels after the MA and GE co-administration. Western blot evaluated the expression of FTO, c-Myc, MRP7, BCRP, and apoptotic proteins.MA showed a significant synergistic effect with GE in GE-resistant NSCLC cells; co-administration of MA with GE induced caspase-related apoptosis in resistant NSCLC cells. Moreover, EGFR downstream molecules, including Akt and MAPKs pathways, were significantly inhibited by the MA-GE combination. Short-term incubation of MA did not alter the efflux of GE; however, after incubation for 24 h, the accumulation of tritium-labeled GE significantly increased. A mechanism study showed that co-administration of MA and GE significantly downregulated BCRP and MRP7 expression in GE-resistant cells; increased N6-methylation was also observed after co-administration. The FTO/c-Myc was determined as target pathways on MA and GE co-administration mechanisms.Our findings provide novel therapeutic approaches for GE-resistant NSCLC by combination use with MA through FTO-mediated N6-demethylation. Though crucial progress for the management of non-small cell lung cancer (NSCLC) has been made in the last 20 years, the overall survival rates of NSCLC are still reasonably low. The 5-year overall survival of NSCLC is only 15% .As an oncogene, epidermal growth factor receptor (EGFR) is frequently mutated and abnormally activated among non-smoking NSCLC patients, driving the progression of NSCLC , 5. HencA few studies have identified the potential mechanisms for GE primary or acquired resistance in NSCLC, including KRAS mutations as well as mutations on EGFR kinase activity sites, ultimately inducing gain of function of such an oncogene, in which the transformation of T790M and C797S in EGFR are the top two forms . MoreoveMeclofenamic acid (MA) is a non-steroidal anti-inflammatory drug (NSAID) that has been reported to promote platinum-mediated kidney injury . In our 2. The resistant sublines were cultured in a GE-free complete medium for at least 2 weeks to eliminate the interference of GE before all the experiments.The GE-sensitive PC9 cell line and H292 cell line were purchased from the Cellular Institute (Cell Bank) of the Chinese Academy of Science . The GE-resistant cells PC9-GR and H292-GR were established by exposing them to increasing concentrations of GE. When the cells could not sustain growth similarly to the parental cell lines under GE treatment, the GE was discarded before the cells restored the growth rate. After over 12 months of GE exposure, the PC9-GR and H292-GR cell lines were successfully generated and maintained in 2 μM of GE. MTT assays were conducted to confirm the resistance characteristic of PC9-GR and H292-GR cells. All the above cell lines were cultured in RPMI 1640 medium containing 10% fetal bovine serum (FBS) incubated in a humid atmosphere containing 5% CO3) were seeded into 96-well plates overnight. Then, different concentrations of GE and MA were treated alone or in combination for 48 h. After incubation, MTT  was added to the 96-well plates and incubated at 37°C in the dark for 4 h. The supernatants were discarded, and the formazan was dissolved by DMSO and measured by an iMark microplate reader . The viabilities were calculated by a percentage relative to the DMSO-treated control group. A GraphPad 8.01 software calculated the median inhibitory concentration (IC50) values. The synergistic effects of GE and MA in different NSCLC cells were evaluated by the Chou–Talalay method described previously  for 30 min at RT in the dark. Then, the cells were centrifuged and resuspended in 250 μl of detection buffer and analyzed by MACS Verse flow cytometer . The qualification of apoptotic cells was analyzed by FlowJo VX software .Annexin V-FITC and PI synchronous staining were conducted to evaluate apoptotic cells after GE and MA co-administration in GE-resistant NSCLC cell lines. In brief, cells at a density of 5×10via a custom standard curve.The accumulation of GE in resistant NSCLC cells was evaluated by tritium-labeled GE , purchased from Energy Chemical . The cells were plated into 6-well plates overnight and co-administrated with GE-T (G) and MA for 2 h, 24 h, and 48 h. Then, the cells were collected and the liquid scintillation was detected by a Quantulus™ GCT spectrometer . The accumulation rates of GE were calculated The expression level of EGFR-related downstream pathway molecules, the BCRP and MRP-7 expression level, and FTO and its downstream molecules were evaluated by Western blot assay. Specifically, cells were plated into a 6-well plate overnight and co-administrated with GE and MA. The Triton-X 100 lysis buffer was used to extract the total protein. The concentrations of proteins were qualified by BCA protein Assay Kit . Equal amounts of proteins (20–60 μg) were subjected to 8% to 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) before being transferred onto polyvinylidene fluoride (PVDF) membranes . Non-fat milk (5%) was used as a blocking agent to block the non-specific binding sites of PVDF membranes. The primary antibodies of total EGFR, p-EGFR, p-Akt, p-ERK1/2, BCRP, MRP-7, FTO, and c-Myc were incubated as recommended concentrations with the membrane at 4°C for overnight. Then, the membranes were washed with TBST buffer and incubated with HRP-conjugated secondary antibodies at RT for 1 h. After washing with TBST buffer, the ECL was added to the membrane and an Invitrogen iBright  was used to visualized the protein bands. The relative intensity was calculated by catching the gray level using ImageJ software.–ΔΔCt methods calculated the copy number, and samples were run in triplicate and normalized to GAPDH. Then, the expression levels of mRNAs were reported as fold changes versus control. The primers were as follows: For BCRP, the forward primer (5’-3’) was GCTACACCACCTCCTTCTGT, and the reverse primer (5’-3’) was GGAAGAAGAGAACCCCAGCT. For MRP7, the forward primer (5’-3’) was AGAGTACACCTGTGACCTGC, and the reverse primer (5’-3’) was GAGCACCAACAACAGGGAAG. For GAPDH, the forward primer (5’-3’) was GCACCGTCAAGGCTGAGAAC, and the reverse primer (5’-3’) was TGGTGAAGACGCCAGTGGA.The mRNA expression levels of BCRP, MRP7, FTO, and MYC were determined by qPCR. In brief, the total RNA was extracted from the cells in the presence or absence of MA using TRIzol reagent  according to the manufacturer’s instructions. The concentration of total RNA was measured by ultraviolet spectrophotometry. According to the manufacturer’s instructions, complementary DNAs (cDNAs) were transcribed using RevertAid RT . PCR was performed on Real-Time PCR Detection System  with SYBR™ Green PCR from Thermo Fisher Scientific . The 22. Then, the cells were lysed by Triton X-100 lysis buffer . The radioactivity of the total lysis product was measured by a Tri-Card 4910 liquid scintillation analyzer .The parental and drug-resistant cell lines were seeded into 6-well plates overnight. The cells were incubated with tritium-labeled GE (GE-T) in the presence or absence of MA for 2 h, 24 h, 48 h, or 72 h, respectively, at 37°C containing 5% CO7 cells were seeded into a 6-cm2 dish, then were incubated in the presence or absence of GE and MA for 24 h. The cells were collected after treating with EDTA buffer, centrifuged, and homogenized. The nucleus was discarded by centrifuging at 700g for 10 min at 4°C, and the supernatants were collected. The cell membrane was collected by centrifuging at 14,000g for 30 min at 4°C. Then, the manufactured lysis buffer was used to extract membrane proteins. The composed membrane proteins were subjected to SDS-PAGE subsequently as aforementioned.A membrane and cytoplasm protein isolation kit isolated the cell membrane protein from Beyotime . In brief, 5×106A levels were conducted as previously described  was then used to extract mRNA. The ultraviolet spectrophotometry method was used to determine the concentration of mRNA. Subsequently, the mRNAs were denatured for 3 min at 95°C, followed by cooling in ice directly. The mRNAs were UV cross-linked after being spotted on an Amersham Biosciences Hybond-N+ membrane optimized for nucleic acid transfer . The membranes were shed with TBST buffer, followed by blocking with 5% non-fat milk, and hybridized with anti-m6A antibody  overnight at 4°C. Then, the membranes were washed with TBST buffer and incubated with HRP-conjugated secondary antibodies at RT for 1 h. After washing with TBST buffer, the ECL was incubated and an Invitrogen iBright . The relative intensity was calculated by catching the gray level using ImageJ software.The dot blot assays for detecting mescribed . In brie6A modification of MYC as previously described  were added and incubated with protein A/G agarose beads  in IP buffer overnight at 4°C. The eluent buffer was conducted to elute RNA. The phenol-chloroform was used to purify the RNAs. The qPCR was performed to determine the mRNA level of m6A MYC.The methylated RNA immunoprecipitation (Me-RIP) was conducted to detect the mescribed . In briep < 0.05 was considered statistically significant.Data are expressed as mean ± SD in at least three independent experiments. The significance was determined using one-way ANOVA. GraphPad 8.00 software was used to determine the statistical analysis. 50 values of GE on PC9 and PC9/GR cells were 0.32 and 3.45 μM, respectively. In H292 and H292/GR cells, the IC50 of GE was 0.51 and 5.03 μM, indicating the confirmed resistance profile of PC9/GR and H292/GR cells. The IC50 of MA, in all cell lines, was 4–8 μM.The potential synergistic anti-proliferation effects of MA and GE were determined by MTT assays and fitted using Chou–Talalay methods as previously described . We firs50 value fractions were undertaken in the combined administration of GE and MA. The CI value calculation results indicated that GE and MA showed potent synergistic effects in GE-resistant cells (PC9/GR and H292/GR). In contrast, no significant synergistic effects of GE and MA were observed in parental cells  was calculated. As shown in al cells –L. BaseBased on the combination of GE and MA results, different concentrations of GE and MA were co-administrated in PC9/GR and H292/GR cells to evaluate the apoptotic cell population by flow cytometry. As illustrated in We next evaluated the potential mechanisms of action on the synergistic effects of GE and MA. As shown in Considering the impaired cytotoxicity of GE in resistant NSCLC cells, the synergistic effects may be related to the increased accumulation of GE. Hence, the tritium-labeled GE-based accumulation assays were conducted. As shown in We next evaluated whether MA or combination with GE could alter the membrane drug pumps in GE-resistant NSCLC cells. As illustrated in The total M6A modification in PC9/GR and H292/GR cells was detected by dot blot assays of M6A. As shown in As a first-line drug for patients with NSCLC, GE has shown great application value in the clinics, but its acquired resistance is a massive obstacle for the further benefits of NSCLC patients . The eluThe present study found that MA, an NSAID, showed significant synergistic effects with GE in GE-resistant NSCLC cell lines. Using the Chou–Talalay combination equation, we confirmed that MA and GE showed significantly synergistic effects in GE-selected resistant cells but not in normal NSCLC cells. The caspase-related apoptosis was found after being co-administrated with MA and GE in GE-resistant cell lines. Moreover, the downstream molecules of EGFR pathways were significantly inactivated after combination use, indicating that the administration of MA might enhance the effects of GE. Hence, we further detected whether the accumulation of GE in GE-resistant cell lines increased after MA treatment. The results indicated that MA could significantly enhance the intracellular GE concentration, suggesting that MA may act as a sensitizer of GE in GE-resistant NSCLC cells.As mentioned above, overexpression of BCRP and MRP7 may be responsible for the resistance of gefitinib in NSCLC cells. Hence, the expression levels of BCRP and MRP7 were detected by Western blot in both cell membrane and total cell lysate. MA and MA/GE coadministration significantly decreased both membrane and whole cell lysate expression of BCRP and MRP7, which explained that MA could increase the accumulation of GE in GE-resistant NSCLC cell lines.The downregulatory effects of BCRP and MRP7 may be related to the alteration of mRNA; we evaluated the mRNA expression level of both BCRP and MRP7. Our results indicated that MA and MA/GE coadministration significantly decreased the mRNA expression level of BCRP and MRP7. The M6A modification is a hot spot of mRNA modification, which will reduce mRNA stability . We hypovia the FTO/M6A/MYC axis. Nevertheless, further studies need to unfold because the downregulation of efflux pumps could also be influenced by posttranslational modification, including glycosylation and ubiquitination; whether such changes also participate in the synergistic effects of MA and GE remains to be determined.ABC transporters have been shown to have a significant role in GE resistance in NSCLC cells. In contrast to active site mutation of EGFR, overexpression of ABC transporters potently decreases the intracellular concentration of substrate drugs, ultimately inducing drug resistance . In NSCLThe original contributions presented in the study are included in the article/HC performed the main experiments and analyzed the data. BJ and QZ drafted the manuscript, which HC revised. HC and YZ designed the study and revised the final version of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Chronic rhinosinusitis (CRS) affects 14% of the general population. The Sino-Nasal Outcome Test 22 (SNOT-22) is a reliable instrument assessing the impact of CRS. This study aimed to examine the reliability and construct validity of the translated Bahasa Malaysia version of SNOT-22.This cross-sectional study was conducted in the Otorhinolaryngology clinic in Universiti Sains Malaysia (USM). Seventy CRS respondents and 39 healthy participants were included. The Bahasa Malaysia translated SNOT-22 (bmSNOT-22) was produced using rigorous forward and backward translation. Statistical analyses used included feasibility, Cronbach’s alpha, intraclass correlation coefficient, Pearson’s correlation coefficient and factor analysis.t = 15.33; P < 0.001).The feasibility was 97.2% in the initial test and 100% in the retest. The Cronbach’s alpha was 0.89 in the initial test. The average intraclass correlation coefficient (ICC) was 0.90, indicating good test-retest reliability. The bmSNOT-22 discriminated between the control group and patients (The bmSNOT-22 is reliable, and validity established therefore recommended for Malaysia’s clinicians and researchers as a measurement tool for the outcome in sino-nasal disorders such as rhinosinusitis and nasal polyps. Rhinosinusitis is an inflammation of the sinuses and the nasal cavity; therefore, it is the preferred term to be used rather than sinusitis. As for rhinitis, i.e. inflammation of nasal passage, it can co-exist with sinusitis. The term rhinosinusitis has been used since 1990 and is well adopted globally . The preCRS is a widespread global health disorder, increasing in both incidence and prevalence. It is not a life-threatening disorder. Nevertheless, it has been shown to significantly impact the quality of life (QOL) demonstrated by Hopkins et al. , using aThis study aims to translate and validate SNOT-22 into the Bahasa Malaysia version of SNOT-22 (bmSNOT-22) and to test its reliability in the studied population. A bmSNOT-22 version will be crucially important in helping to establish the desired outcome and improving treatment and predicting the postsurgical improvement in patients with CRS in Malaysia. Research wise, the opportunity to expand a nationwide study dwelling into the QOL of CRS patients using the bmSNOT-22 will provide a wide variety of data to analyse not only in Malaysia but also to the surrounding country that uses the Malay language as their basis of communications, i.e. south Thailand, Brunei and Indonesia.Each participant signed informed consent before inclusion into the study. Permission to use and translate the SNOT-22 was obtained from Piccirillo JF . First, This cross-sectional study was done in Otorhinolaryngology, Head and Neck (ORL-Head and Neck), and Rhinology Clinic in Hospital Universiti Sains Malaysia. Its psychometric properties were assessed against the validated Bahasa Malaysia Version of SF-36 acknowledged as the standard gold instrument. All subjects were between 15 years old–75 years old and could read and write Bahasa Malaysia. The control subjects were healthy Malaysian medical students and health personnel of the School of Medical Sciences from Hospital Universiti Sains Malaysia. The CRS group was diagnosed based on the EPOS 2012 . With an addition of a 10% non-response rate, the sample size required was 72 subjects. As for the sample size determination for reliability, STATA 11.0 software was used to determine its internal consistency. The expected Cronbach’s alpha value that was decided was 0.80; therefore, the minimum sample size required within the 95% lower bound confidence interval of alpha 0.700 is 29 subjects.The sample size for this study was calculated using subject-to-observed variable-ratio The sample size of test-retest reliability was also calculated using STATA 11.0 software using alpha at 0.05 and the power of the study at 0.80, the estimated intraclass correlation coefficient (ICC) was at 0.80. Therefore, the calculated sample size for test-retest reliability is 46 subjects. In addition to that value, another 10% non-response rate was added, giving the sample size requirement of 50 subjects.Statistical analysis was performed using SPSS programme version 20.0 for Windows . Test-retest reliability was calculated by comparing bmSNOT-22 between the first and second visit, using the ICC. The construct validity was tested using confirmatory factor analysis conducted through extracting factors by principal components, followed by Varimax rotation with Kaiser normalisation. Several factors were set to four to determine the number of rotation factors.Seventy CRS patients and 39 healthy controls participated in this study (response rate 97.2%) with an average age of 37.77 years old and 39.49 years old, respectively. The descriptive statistics of each item and scale of bmSNOT-22 and SF-36, including their means, standard deviation (SD), ceiling and floor effects, were evaluated and summated rating scales as shown in t = 5.288; SD = 7.198; P < 0.001). There was a significant difference between the means of the two tests. The mean sum score of bmSNOT-22 was analysed into four respective domains and the findings were summarised in As suggested by the Likert scaling criteria, item means of bmSNOT-22 were all roughly equivalent. The item means, and SD of all the items did not differ (range of mean from 1.10 to 2.64 and SD ranged from 0.933 to 1.486) . Thus, fThe floor effects are present from questions 16 to 21 of the bmSNOT-22, thus indicating limited responsiveness of these questions when evaluated as a single construct. In this study, floor effects or ceiling effects are considered to be present when it is 30% or more. Therefore, when bmSNOT-22 is evaluated as a single construct, floor effects are observed in the Bahasa Malaysia translated items of ‘sad’ (Q19) and ‘embarrassed’ (Q20), but there were no ceiling effects seen. However, the floor effects were diminished when the bmSNOT-22 was analysed as four different subdomains . PynnoneWe chose the same four scales in this study but included the two extra items under rhinological subdomains and excluded Q4 and Q14 in the analysis. The four subscales were rhinological symptoms , ear and facial symptoms (Q7–Q10), sleep function (Q11–Q13), and psychological function (Q15–Q20) . Of all Even in our comparison questionnaire of Bahasa Malaysia version of SF-36, there is a prominent ceiling effect, especially within the role physical (RP) and role emotional (RE) domains that are 54.286% and 40%, respectively. Compared to these two instruments, the Bahasa Malaysia version of SF-36 recorded more patients with minimum scores (floor) and maximum scores (ceiling).The scores for each item in the initial test of bmSNOT-22 are shown in The ICC for each item of the bmSNOT-22 was evaluated for test-retest reliability and presented in Both bmSNOT-22 and the Bahasa Malaysia version of SF-36 were examined against healthy controls. From the analysis, the bmSNOT-22 discriminated between patients known to suffer from CRS and the control group. Mean scores between CRS patients and the control group are shown in P < 0.001; t = 15.33). Thus, there was a significant difference between the means of these two groups. In contrast, the Bahasa Malaysia version SF-36 was also examined against the healthy controls .The mean difference in the sum score was 36.69. It demonstrates statistically significant variability between these groups . Thus, it enables factor analysis to be carried out in this study. Factor analysis was carried out by extracting factors through principal component analysis followed by rotation methods using Varimax rotation with Kaiser normalisation.Kaiser-Meyer-Olkin (KMO) of sampling adequacy measured 0.731 (> 0.6) and Bartlett’s test of sphericity is significant  , the cutderia rasa atau bau’ (Q21), ‘lelehan pasca-hidung’ (Q5) and ‘hingus yang pekat’ (Q6) have the highest load, not within the expected subdomains. For example, we would have expected to have Q6 to load into rhinological symptoms. Still, it is categorised under the ear or facial symptoms and Q21 together with Q5 load almost equally on more than one construct , ‘kecewa/resah/rasa mudah marah’ (Q18), ‘keletihan di siang hari’ (Q15), ‘penumpuan berkurangan’ (Q17), ‘produktiviti berkurangan’ (Q16), ‘malu’ (Q20) and ‘berasa letih ketika bangun’ (Q14) load into psychological function. Rhinological symptoms covers the items were ‘bersin’ (Q2), ‘perlu menghembus hidung’ (Q1), ‘hidung berair’ (Q3), ‘hidung tersumbat’ (Q22) and ‘batuk’ (Q4). ‘Sakit bahagian muka atau tekanan pada muka’ (Q10), ‘sakit telinga/tekanan’ (Q9), ‘telinga terasa mampat/tersumbat telinga’ (Q7) and ‘pening’ (Q8) were categorised under ear or facial symptoms. Sleep function contains three questions: ‘terjaga di waktu malam’ (Q12), ‘kekurangan tidur nyenyak waktu malam’ (Q13), ‘susah untuk tidur’ (Q11) (The other questions have the highest load into the expected subdomains. The items of ‘r’ (Q11) . TherefoIn many descriptive studies, CRS has a greater impact on BP and social functioning than angina, congestive heart failure and chronic obstructive pulmonary disease . The impThe SNOT-22 is a further modification of SNOT-20 where two additional items were measured: i) nasal blockage and ii) loss of sense of taste and smell. The scoring system has been simplified by removing the importance rating. The importance rating is added initially to improve its content validity  . SNOT-22n = 39) and males were 44.3% (n = 31) (n = 58) Malay, 12.9% (n = 9) Chinese and 4.3% (n = 3) from other ethnic background. However, these figures do not reflect the actual multi-racial variation as the predominant Kelantan population is the Malay ethnicity which accounts for 90%–95%. None of the Indian ethnic population was included in this study due to the scarce Indian ethnicity in the Kelantan population.In this study, a total of 70 participants willingly consented to this study, and 55 of them were examined again for the test-retest reliability between 2 weeks and 4 weeks later. All the participants need to fulfil the inclusion and exclusion criteria. The consented patients were recruited from convenience sampling taken from rhinology and general ORL-HNS clinic HUSM. The period taken for this study is 7 months, starting from December 2011 until June 2012. The age distribution among our study participants ranged from 18 years old to 72 years old, with a mean of 37.77 years old. In contrast to Pynnonen et al.  and Brow(n = 31) –17. A vaSNOT-22 and SF-36 scores use the Likert scales assumptions method. It has been widely used for scale construction because of its simplicity and accurately yields reliable scores. In this study, Likert scale assumptions and other necessary assumptions have been determined. The bmSNOT-22 showed equal variances and equal total score variability. Thus, Likert scale assumptions are met. All the items’ means were roughly equivalent in this study and avoiding item standardisation. All the items’ mean scores ranged from 1.10 to 2.64, and standard deviations ranged from 0.933 to 1.486.A high percentage of missing data may indicate problems with the translation process and respondents’ confusion on completing that part of the questionnaire . TherefoThe feasibility of an instrument in measuring health related QOL (HRQOL) is determined by examining the floor effect, which is the number of respondents with the lowest possible score, and the ceiling effect, which indicates the highest possible score –20. TablAssessment of reliability and validity of a questionnaire design is part of establishing a sound psychometrics evaluation . ReliabiAnother form of reliability is stability or repeatability over time that is the test-retest reliability. It is assessed by administering the questionnaire to respondents on two different occasions and examining the correlation between scores. Test-retest reliability correlations for summary scores should be greater than 0.7. It is obtained by correlating the matched responses in the initial and subsequent repeat questionnaires. In this study, the average intraclass correlation coefficient for the bmSNOT-22 is 0.907 at 95% CI. It ranges between 0.841 and 0.946. The narrow width value of 0.105 proved that the bmSNOT-22 has a high test-retest reliability of repeated measures.Validity refers to the appropriateness, meaningfulness and usefulness of the specific inferences made from the total scores. There are various forms of validity. In this study, we construct validity for the bmSNOT-22 using face validity, content, construct and criterion validity. We conducted respondent testing on eight CRS patients and three medical doctors to establish face validity, and the questionnaire appeared appropriate to them, and the bmSNOT-22 was fulfilled.In addition, to construct the validity of an instrument, factor analysis needs to be carried out. In the previous studies in English and Czech versions of SNOT-22, no attempt was made to investigate the grouping of the items in SNOT-22. Studies were done by Pynnonen et al.  and Browlelehan pasca-hidung’ (Q5) and ‘deria rasa atau bau’ (Q21) would load purely into rhinological symptoms, but it loads almost equally onto more than one construct with the highest values within the ear or facial symptom (Q5) and psychological functions (Q21). Question on ‘hingus yang pekat’ (Q6) load purely onto an ear or facial symptom. The other 19 questions have the highest values within the expected subdomains. Therefore, we believe that the usage of bmSNOT-22 in clinical research may help to improve the quality of data produced for clinical management strategies.We construct the factor analysis in this study by extracting factors through principal component analysis, followed by rotation methods using Varimax rotation with Kaiser normalisation. Prior to any factor analysis, sampling adequacy using KMO and significant Bartlett’s test of sphericity were demonstrated. By using exploratory factor analysis with Eigenvalues > 1, six components were produced. However, the scree plot suggested four factors, and based on the original SNOT-22 questionnaire, four subdomains were decided to be used in this study. Based on the study by Pynnonen et al.  and Browt-test was carried out to measure known group validity in detecting expected differences across groups and a P-value of 0.05 or less is considered significant. The results showed t = 15.33; P < 0.001, and the hypothesis is met   .r) to examine the correlation between corresponding domains of the bmSNOT-22 and Bahasa Malaysia version SF-36. It was hypothesised that there should be inter-domain correlations between bmSNOT-22 and Bahasa Malaysia version of SF-36.The concurrent validity of QOL instruments is a measure of agreement between the results obtained from the survey instruments and other instruments acknowledged as the ‘gold standard’ within the same targeted population. The establishment of concurrent validity is part of criterion validity. The validity of the bmSNOT-22 was assessed against the Bahasa Malaysia version SF-36 using a correlation coefficient. In this study, we used the Pearson correlation coefficient  and psychological issues  in bmSNOT-22. BP domains in Bahasa Malaysia version SF-36 were also statistically significant with psychological issues  in bmSNOT-22.The correlation coefficient always lies between −1 and +1. It indicates a perfect positive or negative linear relationship between two variables. Negative correlations were observed between all subdomains within the bmSNOT-22 and RE component of Bahasa Malaysia version SF-36. This means that when an item increases, the second variable will decrease. The majority of the subscales within the bmSNOT-22 were weakly correlated with the eight subscales of the Bahasa Malaysia version of SF-36. However, the subscale of RP in Bahasa Malaysia version SF-36 statistically correlates significantly with ear or facial symptoms (P < 0.05) for two out of eight dimensions: the RP and BP subdomains. The significant correlations between two out of eight dimensions in Bahasa Malaysia version SF-36 and the weak correlations obtained in this present study may have been due to the small sample size (From the analysis done between the bmSNOT-22 scores and the Bahasa Malaysia version SF-36, the correlation was significant (However, despite the weak correlation, its validity can be established by fulfilling content, construct and discriminant validity. Therefore, bmSNOT-22 is a reliable, valid and sensitive tool. Using a larger sample size can determine its psychometric properties more precisely with a plan to validate further within various clinical practices.Lastly, we have ensured that unlike its predecessor, the SNOT-20, the SNOT-22 has the most disease-specific items. We have demonstrated in this study that healthy individuals report significantly lower scores on the SNOT-22. However, patients with other medical conditions may also report some of the symptoms included in the instruments. It is important to note that this instrument should not be used for diagnostic purposes, but it is developed to capture the impact a given disease has on all QOL aspects.The bmSNOT-22 is good for health status measurement in comparison to the standard generic health status questionnaire. All the items within bmSNOT-22 had high communalities. Therefore, it is established that the items share variance, and a good correlation exists between items within the bmSNOT-22. In conclusion, this study has found that the bmSNOT-22 was a valid and easy-to-use instrument. It can be used to facilitate clinical practice and research purposes and to highlight the impact of CRS on patients’ QOL.


Current networks of regulatory air quality monitoring are too sparse to capture these intra-city variations. In this study, we developed a low-cost (60 USD) portable PM2.5 monitor called Smart-P, for use on bicycles, with the goal of mapping street-level variations in PM2.5 concentration. The Smart-P is compact in size (85 × 85 × 42 mm) and light in weight (147 g). Data communication and geolocation are achieved with the cyclist’s smartphone with the help of a user-friendly app. Good agreement was observed between the Smart-P monitors and a regulatory-grade monitor (mean bias error: −3.0 to 1.5 μg m−3 for the four monitors tested) in ambient conditions with relative humidity ranging from 38 to 100%. Monitor performance decreased in humidity > 70% condition. The measurement precision, represented as coefficient of variation, was 6 to 9% in stationary mode and 6% in biking mode across the four tested monitors. Street tests in a city with low background PM2.5 concentrations (8 to 9 μg m−3) and in two cities with high background concentrations (41 to 74 μg m−3) showed that the Smart-P was capable of observing local emission hotspots and that its measurement was not sensitive to bicycle speed. The low-cost and user-friendly nature are two features that make the Smart-P a good choice for empowering citizen scientists to participate in local air quality monitoring.The concentration of fine particulate matter (PM Based on a large body of scientific evidence accumulated in the past decades, the U.S. Environmental Protection Agency (EPA) has concluded a causal relationship between PM2.5 exposure (both short-term and long-term) and mortality [2.5 exposure include, but are not limited to, respiratory and cardiovascular morbidity, cancer risks, and possible harm to the nervous system [Outdoor air pollution is estimated to cause over three million premature deaths per year worldwide, and this number is projected to double by 2050 under a business-as-usual emission scenario . A promis system ,4.2.5 concentrations, for regulatory purposes [2 with continuous regulatory monitoring [2.5 concentration typically varies spatially over short intra-city scales due to variations in land use and source distributions, referred to as spatiotemporal variability [Fixed site monitor (FSM) networks are important tools to monitor ambient air quality, including PMpurposes . Regulatnitoring . Despiteiability ,8.2.5 concentration at the neighborhood scale.Some current air quality management efforts focus on improving spatial and temporal resolution beyond regulatory FSMs, and the paradigm of air pollution monitoring is shifting towards applications of low-cost air sensors . Althoug2.5 monitoring by providing real-time snapshots of PM2.5 concentration profiles along chosen paths. Some mobile systems consist of research-grade monitors mounted in special vehicle-based laboratories [In addition to stationary low-cost sensor networks, mobile sensors can be used to characterize intra-city variations in air quality. Mobile monitoring platforms, such as those based on cars and bicycles, can further improve the spatial and temporal resolution of PMratories ,21,22,23ratories ,27,28,292.5 concentration variations with mobile platforms, repetitive measurements over the same routes are recommended [2.5 sensors offer an opportunity for citizen scientists concerned with local air quality to participate in data collection, thus expanding the spatial and temporal coverage of mobile monitoring.To quantify intra-city spatiotemporal PMommended ,15. Suchommended . Involviommended . Such coommended . A well-ommended . Low-cosThis study aimed (1) to develop a low-cost portable PM monitor, (2) to evaluate its performance against a research-grade instrument, and (3) to demonstrate its potential for mobile deployment with actual street transect measurements. This study is part of a project called “Biking for Science and Health”, whose goal is to develop smart environmental sensors for use on bicycles to monitor heat stress and air quality in urban environments.In the following, the term “monitor” refers to an entire measuring system consisting of a sensor, signal processing, data transmission and storage modules, a power supply, and an enclosure. The low-cost portable PM monitor is called Smart-P. Its design principle is similar to that deployed for Smart-T, a low-cost portable monitor for temperature and humidity for use on bicycles . The keySeveral other researcher groups have developed low-cost PM monitors that can be used in mobile monitoring ,39,40,412.5 and PM10 particle concentrations are measured. In this paper, we focused our evaluation exclusively on its PM2.5 performance. The SDS011 sensor specifications meet several criteria needed for mobile monitoring of PM2.5 concentration in an urban environment. For example, its short corresponding time of 1 s contributes to collecting data in high spatial and temporal resolutions. Its wide detection range of 0.0 to 999.9 μg m−3 also allows measurement of low levels as well as hotspots of PM2.5 concentration.The sensor module of Smart-P is an off-the-shelf SDS011 PM sensor (hereafter referred to as SDS011) manufactured by Nova Fitness Co., Ltd.  . The SDSr > 0.97) between the three SDS011 sensors and good linearity against a regulatory PM2.5 monitor (R2 from 0.55 to 0.71). On an hourly average basis, the three tested sensors had accuracy ranging from 81 to 98% compared with the reference instrument. The accuracy decreased substantially with high relative humidity of more than 80%. Genikomsakis et al. compared an SDS011 sensor to a commercial high-quality optical particle sizing instrument (Model: TSI OPS 3330), which had a U.S. National Institute of Standards and Technology (NIST) traceable calibration [R2 of 0.933 with one-minute average data for a three-day measurement period. Badura et al. simultaneously evaluated four models of off-the-shelf low-cost PM2.5 sensors in a half-year period, including three monitors of each of the following models: SDS011, Winsen ZH03A , Plantower PMS7003 , and Alphasense OPC-N2 . Among the four models, the SDS011 demonstrated the best precision (1-min average data) and the second-best linearity against a reference regulatory-grade PM2.5 monitor [The data quality of the SDS011 is well-documented in the literature, primarily based on stationary measurements. For example, Liu et al. conducted collocation measurements with three SDS011 sensors at a regulatory air monitoring station in Oslo, Norway for a four-month period . Their cibration . The SDS monitor . These sSuccessful use of the SDC011 on bicycles requires solutions to several logistical challenges. In the applications cited above, the SDS011 sensor was used at a fixed location and usually with easy access to A/C power. The sensor readout was achieved via a USB port connection to a computer. Such power and data arrangements would not be feasible for mobile deployment on a bicycle. Potential adverse impacts on data quality may arise due to biking speed ,11. In aWe integrated the electronic components onto a specialized motherboard, as shown in When sampling at 1 Hz, Smart-P has a rated current of 105 mA, corresponding to a power rating of 0.515 W, about 70% of which is consumed by the SDS011 sensor. At this sample rate, a 10,000 mAh power bank, which weighs about 210 g, lasts 95 h. Extended battery life can be achieved by sampling less frequently and putting the SDS011 sensor into sleep mode between sampling intervals. The sleep current is less than 4 mA based on the SDS011 specifications.We designed a 3D-printed enclosure to protect the electronics and the sensor from physical damage and to reduce vibrations during mobile measurements. It houses the electronics and the sensor while allowing air to flow in and out. The enclosure has a dimension of 85 × 85 × 42 mm. The total weight of a Smart-P monitor, including the enclosure, the electronics, and the sensor, is 147 g, comparable to the mass of a typical smartphone.According to the manufacturer, connecting the SDS011 to an inlet tube is optional. If an inlet sampling tube is desired, it recommends that the tube be less than 1 m in length. In our tests, we found that tubes of 1 m in length  reduced the sensor reading to near-zero values regardless of ambient PM levels, presumably due to particle deposition onto the tube walls, including by electrostatic losses. Our final choice for the Smart-P was a Teflon tube with a length of 5 cm. This inlet tube is long enough to ensure that the SDS011 sensor can draw air from outside of the enclosure and is short to reduce particle deposition. Another benefit of a short tube is decreased travel time of the sampled air and therefore a fast response in mobile measurements.2.5 and PM10 concentrations. For each data log, the app records local date and time, GPS coordinates (latitude and longitude), and PM2.5 and PM10 concentrations. The app allows the user to customize the data logging interval from 1 Hz for high-resolution mapping to a long interval  to conserve battery or at times of stable PM concentration. The app utilizes the built-in real-time clock and the GPS module of the smartphone to obtain the date, time, and location data. This arrangement reduces the cost of Smart-P. Data are stored locally in the paired smartphone as comma-separated values (CSV) files, with file names representing the exact end date and time (in the format “YYYYMMDDHHMMSS”) of the mobile measurements. Users can inspect the saved data by exporting them to a computer and visualizing them. Privacy-sensitive information, such as GPS coordinates at the start and end of a street transect measurement, can be removed manually before sharing the data or depositing it to a public archive.We developed the YNCenter app for data displaying, time recording, position geolocating, and data storage in real-time using a smartphone. The app turns the user’s phone into a data logging and geolocating device. Its user interface is shown in The app, in its beta version, was only available for Android devices at this time. An app with the same functionality will be available for the IOS operating system in the near future.The step-by-step standard operating procedure of Smart-P is illustrated in 2.5 with hourly resolution. The BAM-1020, based on beta ray attenuation, is a U.S. regulatory-grade federal equivalent method [−3 and a range of 0–1000 μg m−3 [Collocating portable monitors with stationary reference air monitors prior to mobile deployment is a common practice in the field of using portable monitors for air quality monitoring ,52,53,54t method . The BAM0 μg m−3 . The staWe installed four Smart-P monitors beside the trailer under a rack, as shown in The collocation measurements took place in July 2021. Measurements were made intermittently due to summer storms. In total, six measurements were conducted, with each measurement lasting 7 to 52 h. The Smart-P monitors recorded data every 30 s; these were averaged to hourly values for comparison with the measurement made with the BAM-1020 monitor.For the six measurements at YCFS, we collected 17,891 to 19,664 readings, covering 152 to 163 valid hours (see R2). Other error statistics included the root mean square error (RMSE), the mean absolute error (MAE), and the mean bias error (MBE).We used linear regression to quantify bias and linearity between two monitors. Biases were evaluated with the slope and intercept of the regression. Linearity was evaluated with the coefficient of determination  were placed side-by-side on a desk in an apartment. One goal of the indoor tests was to evaluate whether the Smart-P could capture PM−1. The New Haven test took place on 15 June 2021, from 4:02 PM to 4:52 PM. Four Smart-P monitors  were mounted on the front windshield of a passenger car, with the inlets facing forward. We measured a 15 km street transect across major parts of Yale University, its adjacent residential neighborhoods (East Rock and Dixwell), and downtown New Haven. The transect mainly consisted of one- and two-lane arterial streets. At the time of the test, the nearest regulatory air monitor  reported an hourly average PM2.5 concentration of 7.5 μg m−3.The second type of test was mobile measurements using a passenger car in New Haven, CT, USA, and Hangzhou, Zhejiang, China. In both measurements, data were logged at 1 Hz and the driving speed varied from 0 to 90 km h2.5 at the nearest regulatory monitoring station  was 74 μg m−3.The Hangzhou car test took place on 17 April 2021, from 9:40 AM to 12:40 PM. One Smart-P monitor (ID: 512) was mounted on the roof rack of a passenger car with the inlet facing forward. We measured a 30 km transect across three major urban districts in Hangzhou, including Shangcheng, Gongshu, and Xihu. The transect, consisting of multi-lane arterial roads and elevated expressways, crossed a variety of urban landscapes, such as high-rise residential buildings, high-rise office buildings, recreational parks, industrial areas, and construction zones. At the time of the test, the ambient hourly-average PM−1. The New Haven bicycle test took place on 4 August 2021, from 11:00 AM to 11:30 AM. We mounted four Smart-P monitors  on the rear rack of a bicycle with two inlets facing left and two facing right to reduce the effect of flow blockage by the cyclist. We measured a 5 km transect around the Yale University main campus. At the time of the test, the nearest regulatory air monitor  reported an hourly average PM2.5 concentration of 8.5 μg m−3.The third type of test was also carried out in outdoor conditions, with the Smart-P mounted on a bicycle. The bicycle measurements were conducted in New Haven and in Nanjing, Jiangsu, China. In both measurements, data were logged at 1 Hz and the cycling speed varied from 0 to 23 km h2.5 concentration of 41 μg m−3.The Nanjing bicycle test took place on 14 July 2021, from 5:24 PM to 6:00 PM. We mounted a Smart-P monitor (ID: 508) on the handlebar. We measured a 6 km transect centered at the Nanjing Olympic Sports Stadium. At the time of the test, the nearest regulatory air monitor  reported an hourly average PM2.5, including U.S. EPA federal reference and equivalent methods, are primarily designed for stationary use at designated sites. As an example, the Met One BAM-1020 monitor operates at 100 to 230 volts alternating current and is 310 mm high × 430 mm wide × 400 mm deep. The BAM-1020 was designed to mount in a temperature-controlled enclosure. The sampling inlet was designed to mount through the roof of the enclosure. Hence, it is logistically challenging to operate it on a mobile platform, such as a passenger car or a bicycle. Moreover, reference monitors typically report data on an hourly basis, as opposed to the up to second-by-second basis of many low-cost sensors, including the SDS011 sensor in the Smart-P. Therefore, side-by-side comparison to a reference monitor was not conducted in these additional tests. Nevertheless, to indicate whether the Smart-P readings were reasonable, hourly average PM2.5 concentration data were obtained from the nearest regulatory monitor wherever possible.For these additional tests, a reference monitor was not placed next to the Smart-P monitors. This was because reference monitors for PMFor the tests made simultaneously with multiple Smart-P monitors, we quantified the precision, or unit-to-unit variance, among the monitors using standard deviation (SD) and coefficient of variation (CV) . We firs2.5 concentration between each of the four Smart-P monitors and the BAM-1020 monitor at the YCFS. Under the full range of measured RH, the Smart-P monitors showed some biases against the BAM-1020, as indicated by the regression slopes and intercepts. These biases are in part attributable to the differences in physical and chemical properties between the particles used in manufacturer calibration of the SDS011 and real-world ambient particles [articles . An addiarticles ,61.R2 of 0.528 to 0.742  and high (>70%) RH environment tends to underestimate and overestimate PM2.5 concentration, respectively. Across the entire measured RH range from 38 to 100%, these four Smart-P monitors had MBEs from −3.0 μg m−3 to 1.5 μg m−3. The relative biases, that is, the ratio of the MBE to the mean concentration measured by BAM-1020, were 8, −5, −19, and 4% for Smart-P 501, 502, 503, and 504, respectively, based on the entire measured RH range . The SD and CV were higher under high humidity conditions (RH > 70%), in the range of 2.2 to 2.5 μg m−3 and 10 to 12%, respectively, but calibrations to correct for RH could reduce the effects [−3 and 9%, respectively, based on the comparison to each other among the four monitors . During the second event, they captured a smaller PM2.5 peak of 12 to 13 μg m−3 at about the same time (19:10). The two cooking events verified that Smart-P can measure short emission episodes of both high and low emission intensities. The variations among the monitors were within the rated relative error by the manufacturer, i.e., ±15%. For both cooking events, the readings were highly precise, as indicated by R2 of 1 for the noon high emission episode . Approximately 60% of the Smart-P readings were below 7.5 μg m−3, with a mean of 3 to 4 μg m−3, depending on the Smart-P monitor. The remaining Smart-P readings were above 7.5 μg m−3, with a mean of 25 to 35 μg m−3, depending on the Smart-P monitor. These Smart-P readings indicated that the regulatory monitor was not representative of the spatial and temporal variations in ambient PM2.5 concentration within the city area.2.5 concentrations measured with Smart-P 501. The other three Smart-P monitors  showed similar spatial patterns  PM emissions in a given driving cycle of gasoline vehicles [2.5 concentration peaks at the intersection of Dixwell Avenue and Foote Street (Loop 2) at about 16:41 was potentially contributed to by an idling diesel garbage truck, as diesel engines are known emitters of PM2.5 [2.5 [patterns . All fouvehicles . The folof PM2.5 ,64. Howe2.5 [2.5 .−3 (one SD) and 13% based on the CV  based on 1 min average PM2.5 concentrations  was observed on the greenway north of the Nanjing Olympic Sports Stadium at about 17:31. This greenway was adjacent to the south side of a four-lane arterial road (Mengdu Street), where heavy rush-hour traffic was observed at the time of the measurement. In contrast, no elevated level was measured on the north side of Mengdu Street, indicating the potential role of wind direction in near-road air quality [−3 and 66 μg m−3, respectively, were observed at traffic intersections, which can be hotspots due to motor vehicle-related emissions [−3. quality . The oth2.5 concentrations vs. speed  and median values (11 μg m−3). For these seven speed bins (sample size of one bin = 68 to 498), the Pearson correlation between the bin average concentration and bin average speed was statistically insignificant . The narrower range for speed greater than 17.5 km h−1 was caused by a small sample size (≤13 s in one bin).A key difference between mobile and stationary platforms is that mobile platforms involve moving instruments at varying speeds. Travel speed may impact how air enters the sampling tube and instrument chamber, potentially causing artifacts in sensor readings ,11. Heres. speed  for the 9 μg m−3 a. We useThe insensitivity of the background concentration to speed was also observed during the other mobile measurements . These r2.5 concentration, temperature, and RH, and the calibration standard monitor should have the capacity to measure at a high temporal resolution  [2.5 monitors have been shown to improve performance, with laboratory-calibrated monitors and calibration via collocation using multi-variable gain-offset calibration models increasingly improving RMSE over raw sensor data [All the Smart-P results were presented based on manufacturer calibration. These results indicated that even with just manufacturer calibration, Smart-P can provide useful information to citizen scientists for applications such as understanding local air quality trends and identifying emission hotspots. Nevertheless, Smart-P accuracy can be further improved by calibration against a high-quality monitor prior to deployment by collocation . The per, 1 min) . Frequen, 1 min) . Ideally, 1 min) . Calibrasor data ,61,68. Tsor data  or modifHigh precision is necessary to ensure that results from different Smart-P monitors can be merged for mapping spatial patterns when deployed in large quantities. 2.5 concentrations, with some contributions from traffic-related air pollution. Multiple PM2.5 concentration peaks were measured in each city. These PM2.5 peaks were 3 to 50 times higher than the corresponding background concentrations, the latter of which did not appear to be affected by travel speed. The highest peak-to-background ratio was 50 measured in the New Haven car test. The ability to measure these local hotspots is indicative that the Smart-P is ready for monitoring street-level spatial variations in PM2.5 concentration.The street tests conducted in three cities confirmed that the Smart-P responded well to capturing large enhancements in PM2.5 concentration  was observed in a greenway despite sheltering in a dense vegetation barrier from street traffic , lightweight (147 g), low power consumption (4 to 105 mA depending on sampling frequency), good precision (6% in mobile mode), ease of use, and smartphone compatibility to facilitate deployment by citizen scientists. The Smart-P used a low-cost optical sensor (SDS011) to measure the PM2.5 concentration. Although the performance of the SDS011 in stationary monitoring was documented in the literature, its performance in mobile mode was not known. Bicycle motion may impact how air enters the instrument chamber, potentially producing artifacts in sensor readings. We showed that the measurement was not susceptible to bicycle motion. On-street tests suggest that the measurement precision should be sufficient for mapping spatial variations of PM2.5 concentration in urban land with multiple monitors.We reported the development of a portable PMThe Smart-P allows room for future upgrades. Integration of a low-cost temperature and RH sensor onto the motherboard would facilitate the correction of interferences from temperature and RH on the sensor’s PM detection. Further cost reduction may be achieved by replacing its Bluetooth module with a less expensive one and by switching from 3D printing of the enclosure to laser cutting or injection molding. Another improvement is to power the Smart-P with a small rechargeable battery connected to a bicycle phone charger which harvests the mechanical energy from bicycle motion, thus avoiding the need for a power bank.


Baths in cold water are a popular physical activity performed to improve health. This study aimed to determine whether repeated cold-water exposure leads to the up-regulation of antioxidant defenses and whether or not this leads to a reduction in basal and/or acute pulses of oxidative distress in humans. The study group consisted of 28 healthy male members of the WS club (average age 39.3 ± 6.1 years). The study sessions occurred at the beginning and the end of the WS season. During the WS season, the participants took 3-min cold-water baths in a cold lake once a week. Blood samples were collected three times during each session: before the bath, 30 min after the bath, and 24 h after the bath. The activity of selected antioxidant enzymes, including superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), as well as the concentration of lipid peroxidation (LPO) products, including thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD), were determined in erythrocytes. The concentration of TBARS, CD, retinol, and α-tocopherol were determined in the blood plasma, whereas the level of other LPO products, including 4-hydroxynonenal and 8-iso-prostaglandin F2α, were determined in the blood serum. The repeated cold exposure up-regulated most antioxidant defenses, and this led to an attenuation of most indicators of oxidative stress at the baseline and acute pulses in response to cold exposure. In conclusion, due to regular cold exposure, the antioxidant barrier of winter swimmers was stimulated. Thus, short cold-bath sessions seem to be an effective intervention, inducing promoting positive adaptive changes such as the increased antioxidant capacity of the organism. However, all organisms that breathe oxygen are also exposed to the harmful consequences resulting from its transformations. Excess O effects . In aero effects . Oxygen  effects ,4.Oxidative stress occurs due to the increased formation of free oxygen radicals and/or weakened functioning of the antioxidant barrier . An unco2 and the less reactive H2O2 [The antioxidant system includes antioxidant enzymes and non-enzymatic antioxidants. Superoxide dismutase SOD is an enzyme that catalyzes the dismutation reaction of the superoxide anion radical to Oive H2O2 . The resive H2O2 . In addiCold is often used in medicine to reduce inflammation . As a reThis study covered a group of 28 healthy male volunteers (average age 39.3 ± 6.1 years) who were members of a winter swimming club. Only people who regularly (at least once a week) bathed in cold and icy water for at least two previous seasons took part in the study. Before and during the study, the participants did not change their eating habits or physical activity. Eligibility criteria are presented in The measurement of body components was carried out using the bioelectrical impedance analyzer—Tanita BC 418 MA . The body composition analysis of the study participants is presented in The study was approved by the Bioethical Committee operating at Ludwik Rydygier Collegium Medicum in Bydgoszcz of Nicolaus Copernicus University in Toruń, Poland . Subjects participating in the experiment became familiar with the assumptions of the experiment. The study participants were also informed about the possibility of resigning from participation in the experiment at any stage without giving a reason, and they gave their written consent to participate in the study.The winter swimming season usually starts in autumn and lasts until spring, so the study was divided into two stages. The first stage took place at the beginning of the season (BS), i.e., in October, while the second stage of the research took place at the end of the winter swimming season (ES), i.e., in April . During In both stages of the study, the bath consisted of a 3-min immersion in a cold lake to the depth determined by the nipple line. The water temperature was 7.3 °C at BS and 6.5 °C at ES. During the bath, the study participants were dressed in swimwear (slips), a winter hat, and gloves, as is customary during winter swimming. In order to protect their feet from injury, swimmers wore special water shoes. Before entering the water, the study participants performed a short (5-min) moderate-intensity warm-up. The experiment conditions did not differ between the two stages of the study. The study participants were dressed as they were on the first day of the experiment, performed the same warm-up, and immersed themselves in the water to the same depth. Venous blood collection was carried out at a medical point, a part of the bathing infrastructure, located by the beach. Blood for testing was collected by authorized and qualified medical personnel. At each of the two study dates, blood samples were collected three times :∘Before swimming in cold water (baseline) (BS-0);∘30 min after a bath in cold water (BS-30);∘24 h after a cold-water bath (BS-24).At the beginning of the swimming season (BS) (in October):∘Before swimming in cold water (baseline) (ES-0);∘30 min after a bath in cold water (ES-30);∘24 h after a cold-water bath (ES-24).At the end of the swimming season (ES) (in April):2) and a separating gel. Determination of parameters in erythrocytes and blood plasma was performed using blood samples collected into test tubes containing the anticoagulant dipotassium edetate (K2EDTA).The material collected for biochemical tests included venous blood specimens collected in a vacuum system from the basilic vein. For serum collection, blood samples were collected into tubes containing a clotting activator . Concentrations of vitamins A and E were determined using high-performance liquid chromatography (HPLC) with the ProStar System kit with a fluorescence detector . In contrast, the concentrations of 4-HNE and 8-iso-PGF2α were determined using commercial diagnostic kits based on the immunoenzymatic method (ELISA) using a SPECTROstar Nano plate spectrophotometer . All tested parameters were analyzed in duplicate, and the mean values of the tests were given as a result.2O2) solution decomposed by the enzyme. CAT activity was expressed in IU/g Hb. GPx activity was determined according to the method of Paglia and Valentine [SOD activity in erythrocytes was determined using the method of Misra and Fridovich . This mealentine . This meThe TBARS level was determined according to the methodology of Buege and Aust , modifieVitamin A (retinol) and E (α-tocopherol) concentrations were determined using the HPLC method. The mobile phase was an acetonitrile–methanol solution. Vitamin concentrations were determined using the WorkStation Polaris software and expressed in µg/L.To determine the concentration of 8-iso-PGF2α and 4-HNE, ready-made analytical kits based on the competitive enzyme immunoassay method (ELISA) were used. 8-iso-PGF2α was determined using a kit from Cloud-Clone Corp. , while a kit from CUSABIO  was used to determine 4-HNE. The determinations were carried out in accordance with the manufacturers’ instructions. The microplates were coated with monoclonal antibodies specific to the determined parameters. The concentration of the determined parameters was determined using the MARS data analysis software and expressed in pg/mL.p < 0.05 were considered statistically significant.Statistical analysis was carried out using the STATISTICA 12 PL package . The obtained results were subjected to statistical analysis using a one-way analysis of variance (ANOVA) test and post-hoc analysis (HSD Tukey’s test). While performing the analysis, the assumptions of the ANOVA test regarding the homogeneity of variance (Levene’s test) and the evaluation of compliance of the analyzed variables with the normal distribution (Kolmogorow–Smirnov test) were considered. The results were presented as the arithmetic mean ± standard deviation (SD). Differences at the significance level of p < 0.001) than at BS-0, while at BS-24 it was almost twice as high (p < 0.001) than at BS-0. Statistically significant differences were observed when comparing the concentration of TBARS in the erythrocytes at BS and ES (p < 0.001) than at BS-0. Similarly, at ES-30 and ES-24, the concentration of TBARS in erythrocytes was approximately 44% (p < 0.001) and 61% (p < 0.001) lower, respectively, than at BS-30 and BS-24.This study showed a statistically significant increase in the concentration of TBARS in erythrocytes as a result of bathing in cold water at BS . At BS-3S and ES . The conp < 0.001) at BS-30 and by about 17% (p < 0.001) at BS-24 compared to BS-0. At ES, the changes in TBARS concentrations in the blood plasma were opposite of those at BS. At ES-30, the concentration of TBARS in the blood plasma decreased by about 13% (p < 0.01), while at ES-24 it was about 43% (p < 0.001) lower than at ES-0 (p < 0.001) than at ES-30. In comparing the results of the TBARS concentration measurement in plasma at BS-0 and ES-0, no difference was found. However, the concentration of TBARS in the blood plasma at ES-30 was lower by about 28% (p < 0.001) than at BS-30. Moreover, this level at ES-24 was about 55% (p < 0.001) lower than at BS-24 . At BS-24, it was more than three times higher than at BS-0 (p < 0.001). A significant increase in the concentration of CD in erythrocytes was also observed in the tests carried out at ES (p < 0.001) higher, and at ES-24 it was about 94% (p < 0.001) higher than ES-0. No differences were observed in the results when measuring the concentration of CD in erythrocytes at ES and at BS  and more than three times (p < 0.001) higher after than before swimming, respectively. At ES-30, the CD concentration increased by about 62% (p < 0.001) compared to ES-0, and the concentration of this LPO product at ES-24 was lower (p < 0.05) than at ES-30 (p < 0.001) at ES-0 than at BS-0, lower by 48% (p < 0.001) at ES-30 than at BS-30, and lower by 74% (p < 0.001) at ES-24 compared to BS-24  higher, and at BS-24, it was about 25% (p < 0.001) higher, than BS-0 (p < 0.01) compared to BS-0. Comparing the concentration of the examined parameter at ES and BS, significant differences in the concentration of 8-iso-PGF2α in the blood serum of the subjects were observed. At ES-30, this concentration was about 37% (p < 0.001) lower, and at ES-24, it was about 42% (p < 0.001) lower, than BS-30 and ES-24, respectively (p < 0.001) lower than at BS  at BS-30 and by about 30% (p < 0.001) at BS-24 compared to BS-0. At ES-30, no statistically significant change in CAT activity was observed, while at ES-24, the activity of this enzyme was about 17% (p < 0.05) higher than at ES-0 (p < 0.001) compared to ES-0 (p < 0.001) lower than ES-0 and, at the same time, lower (p < 0.001) compared to the activity at ES-30. Comparing the activity of SOD in erythrocytes at BS and ES, statistically significant differences were observed (p < 0.001) higher than at ES-0. Moreover, the activity of this enzyme at ES-24 was about 42% (p < 0.005) higher than at BS-24. On the other hand, there were no changes in GPx activity in the erythrocytes 30 min after the bath (p < 0.001) than at BS-0. At ES, no changes in GPx activity were observed 30 min after winter swimming (p < 0.001) and twice as high than at BS-30 and BS-24, respectively  at BS-30 compared to BS-0 was observed  seems to be a critical substrate for human cold tolerance and habituation to cold, as cold adaptation causes the deiodination of thyroxine (T4), thus promoting increased blood triiodothyronine (T3) levels [Low levels of oxidative stress may positively affect an organism by stimulating the antioxidant response and inducing adaptation changes. It was observed in the presented study that regular winter swimming leads to an increase in the activity of the main antioxidant enzymes. Interestingly, in the experienced winter swimmers with at least two years of winter bathing examined in this study, the antioxidant barrier seems to be weaker at BS, suggesting that adaptation to low temperatures is not permanent. This may suggest the need to continue the research for more than one autumn–winter season to assess the durability of adaptation changes to cold due to regular winter swimming. The influence of cold on the human body has been studied for many years. However, the vast majority of studies on cold focus on its impact on the effectiveness of post-workout regeneration in the context of reducing the oxidant–antioxidant imbalance ,71,72,73) levels . A proba) levels  indicate) levels . In thisIn conclusion, regular cold exposure during the winter swimming season causes beneficial changes in oxidant–antioxidant parameters. These changes may translate into improved health and reduced risk of lifestyle diseases. The research results may contribute to the dissemination of winter swimming by demonstrating the beneficial changes caused in the human organism due to this activity. Exposure to low ambient temperatures during a few-minute cold-water bath in the autumn and winter period causes a disturbance of the oxidant–antioxidant balance towards the intensification of oxidation processes, as evidenced by the increase in the concentration of lipid peroxidation indicators in the blood of the subjects. There was no significant contribution of vitamins A and E to antioxidant defense after exposure to cold in experienced winter swimmers, which may suggest that additional supplementation with these vitamins for winter swimmers is not justified. The antioxidant barrier in experienced winter swimmers is strengthened when stimuli stimulate the organism in the form of regular, several-minute exposures to cold. In summary, regular winter swimming does not seem to be an excessive burden for the organism in terms of the intensification of oxidative processes. Moreover, performed once a week in 3- to 5-min sessions, it effectively stimulates the organism to develop adaptive changes. Thus, several-minute sessions of winter swimming once a week can be recommended as an effective method to improve health by inducing positive adaptive changes and strengthening the organism’s antioxidant barrier.